Development of artificial compressibility for smoothed particle hydrodynamics with application to intense fuel sloshing in aircraft wings

Abstract

Sloshing describes the behaviour of a liquid inside the structure containing it, and is an important field of research in engineering problems involving liquids. Accurately predicting fluid dynamics and the interaction with the exciting structure, is crucial for designing safe and efficient liquid transport. An overlooked occurrence of sloshing is in the aviation sector, where hydroelastic interaction between lightweight wing structures and distributed internal storage induces intense sloshing conditions, leading to amplified dissipation of the wing dynamics.

In analysing the influence of sloshing in systems involving fluid-structure-interaction (FSI), computational fluid dynamics is commonly employed. Mesh-free methods, such as smoothed particle hydrodynamics (SPH), are valuable due to their Lagrangian properties enabling the capture of complex fluid topologies and nonlinear surface dynamics. However, classical SPH approaches based on weak compressibility (WCSPH) often suffer from acoustic effects, resulting in noise in the pressure field and hydrodynamic loading, amplified in intense sloshing conditions and having a detrimental influence on FSI solutions.

This work developed an alternative SPH approach based on artificial compressibility (ACSPH), capable of capturing truly incompressible SPH solutions while retaining the beneficial properties of WCSPH schemes. ACSPH was developed and validated against general hydrodynamics problems, highlighting advantageous properties when compared to its weakly compressible counterpart; namely the ability to predict noise-free pressure fields in strong fluid-impacting conditions, with a similar solution cost.

Applied to intense sloshing representative of excitation conditions in aircraft wings, with FSI coupling alongside relevant structural models, ACSPH consistently demonstrated excellent prediction of pressure fields and loading. Compared against single- and multi-degree-of-freedom excitation experiments, the simulations consistently correlated well with experimental results in terms of fluid-induced dissipation and the FSI interactional dynamics.
This analysis included modelling the complex sloshing inside a scaled-wing experiment, highlighting the adaptability and accuracy of the developed approach. ACSPH emerges as a promising tool for simulating sloshing in complex FSI systems, particularly within the aviation sector.

Date of Award	18 Jun 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Branislav Titurus (Supervisor), Thomas C S Rendall (Supervisor) & Jonathan E Cooper (Supervisor)